This invention relates generally to a pneumatically actuated load carrying transportation system which can be used in transporting cargo or passengers on a single or plurality of vehicles which are driven along a pneumatically sealed duct between different geographical locations. Specifically, the invention relates to an improved conduit and air pumping supply network with necessary valves used in conjunction with the movement of vehicles by differential air pressure through a duct work system itself.
The use of a pneumatic or fluid pressure differential for driving vehicles within a closed duct system is known in the prior art. Systems shown in the prior art suffered from extreme complexity for satisfactory operation of the utilization of extremely high and low pneumatic pressure differentials which increased duct stress limitations and increased energy requirements making the overall feasibility and practicability of such systems doubtful due to extremely high cost and the like. Additional problems with pressure extremes included increased system leakage and loss of pressure and increased problems regarding the seals around the vehicles between the duct and the vehicle. The instant invention provides an improved pneumatically actuated vehicular transportation system which reduces the complexity of the system while providing for improved operational results. The system includes the utilization of a plurality of pumping devices which can move a mass of air and which are deployed in an array of pumping stations, with each station extracting air from one sealed section of the transport duct while taking the same mass of air and forcing it into another sealed section of the duct, with each station having a valving system which is controlled by a switching system, preferably electronic, actuated by the relative position of the vehicle along the transport duct. The transport duct is sealed from adjacent sections by a valve at each pumping station. Sectional sealing of the main transport duct allows air pressure behind the moving vehicle to be increased, with the valve mechanism being operated and switched to an open position when the vehicle has approached a pumping station such that the vehicle may pass through the pumping station with the valve in the open position. Once vehicle passage of the pumping station is accomplished, the main transport duct valve will immediately close allowing the increase of air pressure behind the vehicle. Once the operational velocity of the vehicle is achieved, the system is designed to maintain the vehicle at a constant speed by maintaining a constant pressure differential between the front and rear of the vehicle. The vehicle or train of vehicles is sealed across each end face with resilient material with respect to the duct inner wall surface such that the vehicle inner air pressure and the motivating pressure differential may be maintained. The overall system envisions the use of a plurality of air pumping stations disposed along the vehicle transport duct at particular intervals which can be determined by the operational load and speed requirements of the vehicular system and the functional requirements of the transportation system. Each vehicle may be mounted on wheels, rails or any type of friction reducing surface to reduce the friction between the vehicle and the duct walls. A network of air pressure valves may be utilized for creating increased pressure in certain portions of the duct which may be utilized for stopping the vehicle in conjunction with mechanical wheel brakes.
It is an object of this invention to provide an improved vehicular transportation system utilizing a pneumatic energy source.
It is another object of this invention to provide an improved pneumatic transportation system for cargo and passengers disposed within a closed duct, the system including a pump and valve arrangement to provide pneumatic pressure variations behind and in front of the vehicle utilized for propulsion and a valving system to regulate and maintain pressure variation relative to the vehicle.
But still another object of this invention is to provide a transportation system for urban and rural transport of goods and passengers having improved efficiency, reduced cost per vehicular travel per mile and ease of maintenance reducing overall operating costs utilizing pneumatic energy of the propulsion source.
And yet still another object of this invention is to provide an overall pneumatic system for propelling one or more vehicles within a closed duct system employing pumping devices which increase pressure behind the vehicle and produce pressure reduction in front of the vehicle to provide a pressure differential for driving the vehicle within the duct.
In accordance with these and other objects which will be apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.